In the medical field, it is often necessary to attach instruments and tubes to one another. For example, catheters, syringes, needles and IV tubes must often be connected to one another, so that, for example, hemodialysis and other infusion procedures may be safely performed. Various connection systems permitting attachments of such medical devices are commercially available. For example, many medical devices are manufactured with luer slip or luer lock connectors which are commonplace and used extensively in health care facilities throughout the world. Today, luer connectors are commonly used to connect a variety of vascular, enteral, respiratory, and epidural medical devices, components, and accessories. The International Organization for Standardization (ISO) provides that a luer connector has a “conical fitting with a 6% taper for syringes, needles, and certain other medical equipment.” ISO 594-1:1986. Therefore, these connectors generally comprise round male and female interlocking tubes which are slightly tapered so as to hold together upon gentle insertion. A luer slip connection is made by a friction fitting between the male and female tubes. A luer lock connection comprises an additional outer rim of threading which permits the male and female tubes to be secured or “locked” into position. Luer slip connections are often used to connect the intravenous infusion supply tube to the hub of a cannula placed within a patient's vein. Luer lock connections may be used in similar applications, but especially in those in which it is desired to have a more secure connection between devices. Because luer connections offer near universal fit and compatibility, such connections have become ubiquitous. However, as it is desirable to prevent “misconnections” or connections in which two unrelated delivery systems are mistakenly connected together, in recent years alternative connectors have been developed and brought to the marketplace. Regardless of the connection used for a particular system, the connectors form the same general function of permitting different components to be linked together.
One of the known issues associated with luer and other vascular connection devices is the danger of reflux of blood or other fluids into the infusion apparatus. With blood reflux, small amounts of blood from the patient may be drawn into the infusion apparatus, sometimes resulting in blood clots or blockages within the apparatus and other undesirable complications. Another known issue associated with intravenous catheter connections relates to air ingestion through the catheter into the patient's blood stream. This may occur, for example, when the infusion tube is disconnected from an in-vein catheter, leaving the distal connection/female luer end (the end farthest from the patient) exposed to room air.